Method and apparatus for modifying the exit orifice of a satiation pouch

ABSTRACT

A prosthetic device is described that is positionable within the gastro-esophageal junction region of a patient. The prosthetic device includes a proximal opening and a distal orifice that is adjustable in size prior to and/or following implantation. During use, the prosthetic device is attached to tissue of the gastro-esophageal junction region of the patient, with the device positioned such that food ingested by the patient passes from the esophagus through the proximal opening into the interior of the prosthetic device, and eventually exits the prosthetic device via the distal opening.

PRIORITY CLAIM

[0001] This application is a continuation-in-part of U.S. applicationSer. No. 10/118,249, filed Apr. 8, 2002.

FIELD OF THE INVENTION

[0002] The present invention relates generally to the field of devicesand methods for achieving weight loss in humans, and specifically to theuse of devices implantable within the human stomach for controllingfeelings of hunger and/or limiting food intake.

BACKGROUND OF THE INVENTION

[0003] An anatomical view of a human stomach S and associated featuresis shown in FIG. 1A. The esophagus E delivers food from the mouth to theproximal portion of the stomach S. The z-line or gastro-esophagealjunction Z is the irregularly-shaped border between the thin tissue ofthe esophagus and the thicker tissue of the stomach wall. Thegastro-esophageal junction region G is the region encompassing thedistal portion of the esophagus E, the z-line, and the proximal portionof the stomach S.

[0004] Stomach S includes a fundus F at its proximal end and an antrum Aat its distal end. Antrum A feeds into the pylorus P which attaches tothe duodenum D, the proximal region of the small intestine. Within thepylorus P is a sphincter that prevents backflow of food from theduodenum D into the stomach. The middle region of the small intestine,positioned distally of the duodenum D, is the jejunum J.

[0005] Prosthetic devices for use in controlling obesity are shown anddescribed in U.S. application Ser. No. 09/940,110, filed Aug. 27, 2001and U.S. application Ser. No. 10/118,289 filed Apr. 8, 2002, and U.S.Provisional Application No. 60/379,306 filed May 10, 2002. Theseapplications are owned by the assignee of the present application, andthe disclosures of these applications are incorporated herein byreference. Certain forms of these devices involve positioning aprosthetic pouch in the proximal stomach as shown in FIG. 1B. The pouch2 includes a proximal opening 4 and a smaller distal opening 6 and formsa small reservoir that collects masticated food from theesophagus—thereby limiting the amount of food that can be consumed atone time. As the pouch fills with food, it may distend, impartingpressure against the upper stomach and lower esophageal sphinctercausing the patient to experience sensations of fullness. The pouch mayadditionally or alternatively act as a restrictor, limiting the amountof food intake. The pouch is fixed in place using clips, sutures,suitable adhesives or other means 8 at anchor points around theperimeter of the proximal opening 4.

[0006] The amount by which food intake should be restricted variesbetween patients. It may thus be desirable to increase or decrease theamount of food a patient can ingest by selecting an appropriate diameterfor the pouch's distal orifice. A smaller orifice will cause food todescend from the pouch into the stomach more slowly than will a largerorifice, and will thus limit the amount of food the patient can consumeat one time.

[0007] Satiation pouches may be available in multiple distal orificesizes (and/or multiple pouch sizes) to permit the physician to select asize that is appropriate for the targeted food intake for the patient.Alternatively, satiation pouches may be configured to allow the size ofthe pouch's distal opening to be increased or decreased. This enables aphysician implanting such a device to set the distal opening to a sizeappropriate for a patient. In some cases, it will also allow thephysician to make adjustments to the distal opening after it has beenimplanted. For example, if the patient is not losing weight at a desiredrate, the physician might reduce the size of the distal opening—so thatfood will empty more slowly from the pouch into the stomach. Thephysician might alternatively increase the size of the distal opening ifnecessary if weight loss is occurring too rapidly—or if the patient issuffering from nausea and requires that the pouch be opened to allow thepatient to vomit more easily. The present application describes varioussatiation pouches which have adjustable distal orifice sizes and whichthereby provide the physician with enhanced control over the degree offood consumed by the patient at one time.

SUMMARY OF THE INVENTION

[0008] The present invention includes a prosthetic device positionablewithin the gastro-esophageal junction region of a patient, wherein theprosthetic device includes a proximal opening and a distal orifice thatis adjustable in size prior to and/or following implantation. Duringuse, the prosthetic device is attached to tissue of thegastro-esophageal junction region of the patient, with the devicepositioned such that food ingested by the patient passes from theesophagus through the proximal opening into the interior of theprosthetic device, and eventually exits the prosthetic device via thedistal opening.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1A is a schematic illustration of a human stomach and aportion of the small intestine.

[0010]FIG. 1B is a perspective view of a satiation pouch shownpositioned in the stomach.

[0011]FIG. 2A is a perspective view of a first embodiment of a satiationpouch including a set of distal inserts each having a different distalorifice size.

[0012]FIG. 2B is a perspective view of the satiation pouch of FIG. 2Ahaving one of the distal inserts connected to the pouch.

[0013]FIG. 3A is a cross-sectional side view of the pouch of FIG. 2A.

[0014]FIG. 3B is a cross-sectional side view of one of the distalinserts of FIG. 2A.

[0015]FIG. 3C is a cross-sectional side view of the distal portion ofthe pouch of FIG. 3A, with the insert of FIG. 3B assembled with thepouch.

[0016]FIG. 4A is a perspective view of a second embodiment of asatiation pouch, shown together with devices for increasing and reducingthe orifice diameter.

[0017]FIG. 4B is a perspective view of the pouch of FIG. 4A showing theexpander in use to increase the orifice size.

[0018]FIG. 4C is a perspective view of the pouch of FIG. 4A showing areduction tool in use to decrease the orifice size.

[0019]FIG. 5A is a perspective view of a third embodiment of a satiationdevice.

[0020]FIG. 5B is a perspective view of a fourth embodiment of asatiation device

[0021]FIG. 6A is a front elevation view of a fifth embodiment ofsatiation pouch having an alternative form of adjustable distal opening.

[0022]FIG. 6B is a top plan view of the adjustable restrictor ring ofthe pouch of FIG. 6A.

[0023]FIG. 7 is a side elevation view of a sixth embodiment of asatiation pouch having yet another form of adjustable distal opening,and a tool useable for adjusting the distal opening.

[0024]FIGS. 8A and 8B are side elevation views showing the distal end ofthe tool shown in FIG. 7 in the retracted and expanding positions,respectively.

[0025]FIGS. 9A and 9B are top plan views of the adjustable restrictorring of the pouch of FIG. 33, showing the ring in expanded andcontracted positions.

[0026]FIG. 10 is a perspective view of a seventh embodiment of asatiation device together with a tool used to vary the diameter of thedistal orifice.

[0027]FIG. 11 is a perspective view of an eighth embodiment of asatiation device.

[0028]FIGS. 12A and 12B are perspective views of a ninth embodiment of asatiation device.

[0029]FIG. 13 is a perspective view of a tenth embodiment of a satiationdevice.

[0030]FIGS. 14A and 14B are bottom elevation views of an eleventhembodiment of a satiation device, showing the distal orifice in areduced-diameter configuration and in an expanded-diameterconfiguration, respectively.

[0031]FIGS. 15A and 15B are perspective views of twelfth embodiment of asatiation device. FIG. 15B shows the pouch following reduction of thesize of the distal orifice.

[0032]FIGS. 16 through 18 are side perspective views showing the distalorifice of a satiation pouch being expanded using a variety of cuttingtools.

[0033]FIG. 19A is a side elevation view of a cutting tool for expandingthe distal orifice size of a satiation pouch. FIG. 19B is a detailedview of the region within the circle 19B-19B in FIG. 19A.

[0034]FIG. 20A is a cross-sectional side perspective view of a satiationpouch having an adjustable orifice size.

[0035]FIG. 20B is a partially cutaway side perspective view of the pouchof FIG. 20A illustrating adjustment of the orifice size.

DETAILED DESCRIPTION OF THE DRAWINGS

[0036] The drawings show a number of embodiments of satiation poucheshaving features that permit the size of the distal or exit orifice to bealtered before and/or following implantation. The term “exit orifice”will be used to describe the smallest orifice through which food flowsfrom the interior of the pouch towards the stomach. In referring to thestep of modifying the size of the distal orifice or exit orifice of thedevice, the term “size” will be used to refer to the dimensions that,when modified, will change the rate at which ingested food flows throughthe orifice.

[0037] For the purposes of this application, the term “satiationdevices” or “satiation pouches” will be used to mean prosthetic devicesincluding pouches intended to induce weight loss in one or more of avariety of ways. These include, but are not limited to, physicallyrestricting the amount of food that can be consumed, and/or impartingpressure against portions of the body (e.g. stomach, esophagus,esophageal sphincter, etc) causing the patient to experience sensationsof fullness, and/or affecting levels of hormones or other substances inthe body that control or affect feelings of hunger, and/or affecting theamount of ingested food absorbed by the body.

[0038] The pouch of each described embodiment may be formed of aflexible material that will prevent passage of food through the sides ofthe pouch. Examples of such materials include, but are not limited topolyesters (e.g. Dacron® polyester), ePTFE fabric (e.g. GoreTex® fabricor others), a polyurethane such as ChronoFlex® polyurethane, nylonfabrics, silicone, other polymeric materials, and bio-absorbablematerials (e.g. PLLA, PGA, PCL, poly-amhydride etc). The material may bea composite of compliant, semi-compliant and/or non-compliant materialsthat give different regions of the pouch different degrees of complianceso as to allow/limit expansion of the pouch in various locations. Forexample, it may be desirable to provide the pouch with a fairly elasticexit port to as to prevent occlusion in the event a large piece of foodis ingested and/or to control the exit pressure of food from the pouch,whereas the proximal end of the pouch may be stiffer to prevent bulging.Varying degrees of compliance may also be built into the pouch byvarying the cross-sectional thickness in different regions of the pouch.The material may be coated with a lubricious, bio-compatible, chemicallyinert material, such as paraleyne, to reduce friction on the basematerial's surface which will help prevent sticking and food build up onthe device. The flexible pouch material may be reinforced with,constructed of, or supported by supporting members, such as a soft mesh,a cage structure, ribs, rings etc. The supporting members may be formedof stainless steel, polymer, shape memory materials such as nitinol,shape memory alloys, or shape memory polymers, or thickened regions ofmaterial. The pouch may be constructed so as to be self-expanding, suchthat the pouch springs radially open into an expanded condition uponejection from a deployment device or catheter.

[0039] Implantation of the described devices is preferably performedendoscopically, by passing the devices through the esophagus, preferablyunder endoscopic visualization. Alternatively, the devices may beimplanted using surgical or laparoscopic procedures.

[0040] During implantation the pouch is secured at the gastro-esophagealjunction region G using sutures, clips, adhesives, stents or stent-likestructures, or other suitable means. One suture attachment device founduseful for applying sutures between the pouch and tissue is the“Sew-Right” suturing device available from LSI Solutions of Victor, N.Y.Although the pouch may be secured to the esophageal tissue, it is morepreferable to apply sutures/clips below the Z-line to allow forattachment to the thicker tissue of the stomach wall.

[0041] Each of the described pouches includes a proximal opening and adistal exit port (see openings 4 and 6, respectively, of FIG. 1B).Because of its small volume (which may be on the order of approximately2 cc-300 cc in volume, but is preferably in the range of 10-30 cc), thepouch functions to limit the amount of food that can be consumed at onetime. Over time the food within this reservoir descends into the stomachthrough the exit port.

First Embodiment

[0042] A first embodiment of a satiation pouch having a variable-sizeorifice is shown in FIGS. 2A through 3C. Pouch 10 includes a proximalopening 12, a distal opening 14, and a passage extending between theproximal and distal openings. Inserts 16 a, 16 b are provided forattachment to the pouch 10. Preferably two or more such inserts 16 a, 16b are provided, each with a different sized distal orifice 18 a, 18 b.For example, a collection of inserts may be provided with distalorifices each having different diameters in the range of 6-14 mm (for acircular orifice). Each insert includes a proximal opening 20 surroundedby a rim 22. Rim 22 is proportioned to seat within a recess 24 (FIG. 3A)formed in the interior wall of the pouch 10 when the insert 16 a isplaced inside the pouch with the orifice 18 a extending in a distaldirection. See FIGS. 2B and 3C. The rim 22 may be structurallyreinforced using a ring formed of nitinol, stainless steel, thicksilicone, etc if necessary to insure a snug fit between the insert andpouch.

[0043] Prior to implantation of the pouch 10, the physician selects aninsert having a diameter that is appropriate for the patient. S/he doesso by choosing an insert having a distal orifice size that will causefood to descend from the stomach at a desired rate. Next, the physicianpasses the insert through the proximal opening 12 of the pouch 10 andpresses rim 22 of the insert into engagement with recess 24 of pouch. Itmay be necessary to dilate the distal opening 14 of the pouch while rim22 is being seated within the recess 24.

[0044] The distal face of rim 22 may include bumps 26 as shown in FIG.3B. When the pouch and insert are assembled, these bumps 26 urge theproximal face of the rim against the upper surface of the recess (FIG.3C), so as to prevent accumulation of ingested food in spaces that wouldotherwise be left between them. The connection between the pouch andinsert may be reinforced if desired using sutures or other means. Afterthe pouch and insert are assembled, the pouch is implanted at thegastro-esophageal junction region.

[0045] It should be noted that assembly of the pouch and insert mayalternatively be carried out after the pouch has been implanted. Holes28 (FIG. 3B) facilitate grasping of the insert using forceps or othertools during assembly.

[0046] If the physician determines at a later time (for example, afterhours, days, weeks, months or even years) that an insert having adifferent orifice size would be more appropriate for the particularstage of the patient's treatment, the insert 16 a may be removed fromthe pouch 10 (such as by grasping it using forceps and withdrawing itthrough the proximal opening 12) and replaced with another pouch.

[0047] Although the pouch 10 is shown as having proximal opening 12 thatis larger than the distal opening 14, the pouch may be provided with alarger distal opening 14, including one that is equal to or greater insize than the proximal opening. Such an embodiment might be used, forexample, in a patient for whom it would be desirable to allow thepatient to heal from the initial implantation and/or adjust to thepresence of the implanted pouch before the exit orifice is reduced.After an appropriate healing/adjustment period (for example, at leastone day and as long as approximately two weeks in order to allow thesuture/anchor attachment points to heal), a separate procedure would beperformed to add the insert or other flow restrictive component to thepouch 10, preferably by passing the component down the esophagus towardsthe stomach. During implantation of the insert or other component, itmay be desirable to clear the pouch of any food material that may haveaccumulated in the recess 24. It should also be noted that if ahealing/adjustment period is intended, the pouch design might bemodified slightly so as to minimize the chance that food material willaccumulate within the recess 24.

[0048] Another variation on the concept of adding a flow restrictivecomponent after an initial adjustment period involves initiallyimplanting a base device at the gastro-esophageal junction region, wherethe base device need not be a satiation pouch but is a base to which apouch will be attached following the healing/adjustment period. Forexample, the base may take the form of an annular ring or other devicethat is secured at the gastro-esophageal junction region using sutures,clips, staples etc. The ring may be formed of a variety of materials,including those listed for use to form the pouch. After thehealing/adjustment period, a satiation pouch may then be attached to thebase using screws, snaps, sutures, clips, staples or other fasteners.

[0049] Many variations of the first embodiment are possible and areconsidered within the scope of applicant's disclosure. For example, theinserts may be replaced with other types of interchangeable componentsthat add a larger or smaller orifice to the pouch. For example, one suchcomponent may be similar to the inserts 16 a, 16 b but attach to theexterior of the pouch rather than being seated in the pouch interior.Also, the inserts or alternative components may be attachable to thepouch using other means such as sutures, clips, adhesives, etc.

Second Embodiment

[0050]FIG. 4A shows a second embodiment of a satiation pouch 30. Pouch30 includes a distal orifice 32 having a size that may be increased ordecreased prior to or following implantation. A ductile ring 34 islocated at the distal portion of the pouch, near the distal orifice 32.The ring is preferably formed of a malleable, ductile material (e.g.annealed stainless steel, copper or other metal, or plastic). It may beshaped in a spring configuration as shown, or it may have a stent-likeor other type of configuration. Ring 34 may be on the interior orexterior surface of the pouch 30, or embedded within the pouch material.

[0051] Pouch 30 is provided with tools for use in increasing anddecreasing the diameter of the ring 34 so as to increase/decrease thesize of the distal orifice 32. For example, an expansion tool make takethe form of a balloon dilator 36 positionable within the pouch and theninflated as shown in FIG. 4B to expand the ring 34. Another examplemight be an expandable basket-type catheter. A reduction tool 38 mayhave an umbrella-like configuration as shown in FIG. 4A. During use, theoperative head 39 of the tool 38 is placed in its closed position andpassed through the pouch and out the distal orifice 32. Once outside thedistal orifice, the head 39 is expanded, drawn in a proximal directionsuch that it surrounds the ring 34 (FIG. 4C), and then moved to theclosed position to press the ring into a smaller-diameter configuration.Afterwards, the tool 38 is withdrawn from the pouch.

[0052] In this and all of the described embodiments, modifications tothe exit orifice size may be performed at various different stages inthe patient's treatment. For example, if a physician determinesfollowing implantation of the pouch (for example, after hours, days,weeks, months or even years) that a prosthesis having a differentorifice size would be more appropriate for the particular stage of thepatient's treatment, the necessary tools may be passed through theesophagus and used to modify the orifice size. As another example, thepouch may be initially implanted with a large (e.g. as large as, orlarger than, the proximal opening) exit orifice. Then, following anadjustment period and/or healing of the sutures/fasteners etc. at theimplant site, a second procedure is performed to modify the exit orificeto a desired size.

[0053]FIGS. 20A and 20B illustrate another pouch in which malleablematerial may be used to provide adjustability to the exit orifice. Pouch30 a is provided with an exit orifice 32 a and an adjustment orifice 32b, which share a common wall 33. The pouch 30 a is constructed such thatexpansion of an expansion tool (e.g. balloon dilator 36) withinadjustment orifice 32 b reduces the size of exit orifice 32 a, such asby deforming common wall 33 towards the exit orifice 32 a as shown inFIG. 20B. Likewise, use of the expansion tool within exit orifice 32 awill deform common wall 33 away from the exit orifice to increase thesize of the exit orifice. A portion of the pouch, such as the wall 33 orrings/bands surrounding the distal and adjustment orifices, ispreferably formed of a malleable material to allow the exit orifice 32 ato retain it's adjusted size unless its size is further altered usingthe expansion tool.

Third and Fourth Embodiments

[0054] A variation on the second embodiment is the third embodimentshown in FIG. 5A. The third embodiment includes a pouch 40 having anannular web 42 at its distal end, forming a distal orifice 44. Examplesof suitable materials for the webbing 42 include those listed above foruse with the pouch. A low yield-strength ring 46 is connected to theexterior perimeter of the webbing. To increase the diameter of theorifice 44, a dilation tool such as dilator 36 of FIG. 4A is passedthrough the orifice 44 and expanded to expand the ring. The expandedring draws the webbing radially outwardly, thereby increasing the sizeof the orifice 44. A reduction tool such as tool 38 of FIG. 4A may beused to compress the ring to a smaller-diameter size and to therebyreduce the diameter of the orifice 44.

[0055] The pouch 40 a of the fourth embodiment, shown in FIG. 5B,operates in similar fashion to that of the third embodiment, butincludes webbing 42 a and a ring 46 a that extend radially outwardlyfrom the distal orifice 44 a.

Fifth and Sixth Embodiments

[0056] Referring to FIGS. 6A and 6B, a fifth embodiment of a pouch 50may alternatively be provided with a restrictor ring 52 surrounding theexterior of the pouch—near the distal opening. Ring 52 may be expandedby applying expansive radial forces from within the inner diameter ofthe ring (e.g. using a dilator as described or by positioning the jawsof a grasper within the funnel and then separating the jaws), orcompressed using compressive forces applied to the exterior of the ring(e.g. by positioning the ring between the jaws and then closing themslightly). This expansion/compression may be performed prior toimplantation, or after the pouch has been implanted.

[0057]FIG. 7 shows a third alternative embodiment of a pouch 60 havingan adjustable distal opening. The FIG. 7 embodiment is similar to theFIG. 6A embodiment in that it relies upon expansion/contraction of arestrictor ring 62. Restrictor ring 62 is positioned inside the pouchnear the distal opening. A pair of opposed slots 64 are formed in theinterior surface of the ring 62. An endoscopically-controllableadjustment tool 66 includes a pair of extendable pins 68 at the distalend of an elongate shaft 70. Actuators 72 a,b on the proximal end of theadjustment tool 66 control extension of the pins between the retractedposition (FIG. 8A) and the extended position (FIG. 8B). To adjust thediameter of the pouch 60, tool is inserted through the pouch with thepins 68 in the retracted position. Pins 68 are aligned with slots 64 inthe ring 62 and are then extended using actuator 72 a. As they extend,the pins 68 slide into the slots 64. Next, the user rotates the tool 70about its longitudinal axis, in either the clockwise orcounter-clockwise direction. Rotation of the tool expands or contractsthe ring, depending on the direction of rotation. After the ring sizehas been adjusted, the pins 68 are retracted using actuator 72 b, andthe tool 66 is removed from the pouch 62.

Seventh through Ninth Embodiments

[0058] An inflation medium such as gas or saline may be used to affectan increase or decrease in the distal orifice size, either before orafter the pouch has been implanted. For example, in the seventhembodiment shown in FIG. 10, pouch 80 includes an inflatable annularregion 82 adjacent to the distal orifice 84. An endoscopicinflation/deflation tool 86 is passed through the oral cavity and intothe pouch to inject and/or withdraw inflation medium using aninflation/deflation needle 88 insertable into an inflation port in theregion 82. The region 82 may be an integral portion of the pouch 80, orit may take the form of an inflatable ring 82 a as shown on the pouch 80a of the eighth embodiment, which is shown in FIGS. 11A and 11B. FIG.11A shows the ring undergoing expansion, while FIG. 11B shows the ringsufficiently expanded to open (optional) pleats 89 in the pouch 80 a.

[0059] Pouch 90 of the ninth embodiment (FIG. 12) includes a pair ofannular inflation chambers 92, 94 joined by a bi-directional valve 96such that inflation medium displaced from one chamber passes throughvalve 96 into the other chamber. If it is desired to increase thediameter of distal orifice 98, a dilation tool (such as tool 36 of FIG.4A) is positioned within the orifice 98 and expanded, causing inflationmedium in the chamber 94 to pass through valve 96 and into chamber92—thereby allowing ingested food to flow more freely through orifice98. To decrease the diameter of distal orifice 98, the dilation tool isdilated against the upper chamber 92, to cause displacement of inflationmedium into the lower chamber 94 and thereby to cause chamber 94 toexpand radially inwardly to decrease the diameter of orifice 98.

Tenth Embodiment

[0060] Pouch 100 of the tenth embodiment (FIG. 13) uses a zipperconfiguration (similar to that found on plastic storage bags) toincrease or decrease the size of the distal orifice. A longitudinal cut102 is provided in the pouch wall. A zipper carriage 104 is slidable ina proximal direction along the cut to separate the edges 106 a, 106 band to thus increase the size of the distal orifice 108. Movement of thecarriage 104 in the distal direction joins the edges 106 a, 106 btogether to decrease the size of the distal orifice 108.

Eleventh Embodiment

[0061]FIGS. 14A and 14B show the distal end of an eleventh embodiment ofa pouch 110. The distal end of pouch 110 includes a diaphragm 112defining distal orifice 114. The diaphragm 112 is similar to the shutterof a camera in the sense that it includes leaves 116 that are rotatableto increase or decrease the distal orifice 114, depending on thedirection of rotation. Various mechanisms may be used for rotating thediaphragm, including a manual screw-type actuator engageable by anendoscopic tool passed through the oral cavity and into the pouch, or amicroelectromechanical motor activated from an endoscope accessory underdirect visualization or activated wirelessly from outside of thepatient's body.

Twelfth Embodiment

[0062] In accordance with a twelfth embodiment of a pouch 120, the pouch120 includes a drawstring 122 surrounding the distal portion of thepouch. The string may be held in position by feeding it through a sleeve(such as is the case with drawstring pants) or through spaced apartbelt-loop type loops. The size of the distal orifice 124 is reduced bypulling on the free end 126 of the drawstring, causing it to cinch thepouch 120.

Cutting Tools

[0063] Another technique that may be used to increase the size of thedistal orifice of a satiation pouch is to use a cutting tool to cut alarger opening into the pouch. If performed on a pouch located withinthe body, the tool is an endoscopic tool that is introduced through theesophagus and into pouch, preferably under visualization.

[0064] If the pouch is tapered towards its distal end, removing asection of the distal end will increase the orifice size. FIGS. 16through 19B show tools that may be used for this purpose.

[0065]FIG. 16 shows pouch 2 positioned within a stomach S. Endoscopicscissors 130 are passed through the esophagus and into the pouch 2, andare used to trim the distal end off of the pouch 2, thereby increasingthe size of distal orifice 6. In any of the cutting tool embodiments,the pouch 2 may include markings 132 which indicate where cuts should beformed to achieve various orifice diameters.

[0066] Referring to FIG. 17, the distal end of the pouch 2 may be openedusing an endoscopic electrode, such as a bi-polar or monopolar RFelectrode wire 134 that may be energized and drawn across the pouchmaterial to remove a portion of the pouch 2. A variety of electrodeconfigurations may be used, including the “bow” configuration shown, awire having a distal tip electrode, or a plurality of wires 134 aconfigured in a basket-type arrangement as shown in FIG. 18. Such abasket-type arrangement may be expanded into contact with the pouchusing a balloon 136. Alternatively, the wires may be shape-memory wirespre-formed to the expanded positioned and contained within a sheathuntil they are positioned within the pouch, and then released into theirexpanded position to perform the cutting operation.

[0067] Other forms of cutting-type tools may also be used to increasethe distal orifice size on a satiation pouch. For example, the pouch maybe incised with a laser directed onto the wall of the pouch, or using ajet of a chemical substance selected to dissolve a portion of the pouchbut to also be well-tolerated by the gastric mucosa and the patient. Inone embodiment, the pouch may be made of a material that is not affectedby the chemical, with a distal cuff on the pouch that is readilydissolved by the chemical. Chemical is then directed on the cuff if itbecomes necessary to increase the orifice size.

[0068] As yet another example, a cutting device similar to anaortic-punch used for cardiovascular applications may be used to enlargethe distal orifice of a satiation pouch. Referring to FIGS. 19A and 19B,punch device 138 includes a hollow elongate shaft 140 fluidly coupled toa suction port 142. A rod 144 extends through the shaft 140 and a punchtip 146 is carried by the rod 144. Sharp cutting edges 148 are formedalong the proximal perimeter of the punch tip 146. An actuator 150coupled to the rod 144 moves the punch tip 146 towards and away from theend of the shaft 140.

[0069] During use, the instrument is passed through the pouch such thatthe punch tip 146 extends out the distal orifice of the pouch. The shaft140 is moved laterally to cause a portion of the pouch surrounding thedistal orifice to be captured between the punch tip 146 and theperimeter of the shaft 140. The user manipulates the actuator 150 todraw the punch tip 146 in a proximal direction, causing the cuttingedges 148 to slice through the captured portion of the pouch. Suctionapplied to the suction port 142 removes the removed fragments of thepouch from the operative site. The process is repeated until the distalorifice has been increased to the desired size.

[0070] It should be noted that, although these tools describe use ofcutting tools to cut along the circumference of the pouch, a pouch mighthave its distal orifice size increased by simply forming a longitudinalcut adjacent to its distal end.

[0071] Various embodiments of satiation devices and methods forexpanding exit orifices have been described herein. These embodimentsare given by way of example and are not intended to limit the scope ofthe present invention. It should be appreciated, moreover, that thevarious features of the embodiments that have been described may becombined in various ways to produce numerous additional embodiments.Also, while various materials, dimensions, shapes, implantationlocations, etc. have been described for use with disclosed embodiments,others besides those disclosed may be utilized without exceeding thescope of the invention. Lastly, while the pouches have been describedfor use in controlling feelings of hunger, the barrier devices describedherein may be equally suitable for use with other prosthetic devicespositionable within the body, including prosthetic valves implanted inthe lower esophagus or proximal stomach for controllinggastro-esophageal reflux disease (GERD).

What is claimed is:
 1. A method of positioning a prosthetic devicewithin a patient having an esophagus, a stomach, and a gastro-esophagealjunction region, the method comprising the steps of: providing aprosthetic device having a proximal opening and a central passage;securing the prosthetic device at the gastro-esophageal junction regionof the patient, with the prosthetic device oriented such that foodingested by the patient passes from the esophagus into the proximalopening and through the central passage, and exits the prosthetic devicethrough an exit orifice into the interior of the stomach; and modifyingthe size of the exit orifice.
 2. The method of claim 1 wherein themodifying step is performed after the securing step.
 3. The method ofclaim 1 wherein the modifying step is performed prior to the securingstep.
 4. The method of claim 1 wherein: the prosthetic device includes apouch having a distal opening, and the method further provides a firstcomponent attachable to the pouch, the first component including adistal orifice having a size different than a size of the distalopening; the modifying step includes attaching the component to thepouch such that ingested food exiting the central passage flows throughthe distal orifice and into the stomach.
 5. The method of claim 4,further including the step of replacing the first component with asecond component, the second component having an second distal orificehaving a size different from the size of the first distal orifice. 6.The method of claim 4, further including the step of removing thecomponent from the pouch to further modify the size of the exit orifice.7. The method of claim 4 wherein the first component includes a flowrestrictive insert positionable within the central passage of the pouch.8. The method of claim 4 wherein the first component includes a flowrestrictive device attachable to an exterior portion of the pouch. 9.The method of claim 1, wherein the prosthetic device includes adeformable member coupled to the prosthetic device, and whereinmodifying step includes deforming the deformable member to modify thesize of the exit orifice.
 10. The method of claim 9 wherein thedeformable member is formed of malleable material.
 11. The method ofclaim 9 wherein the deformable member is formed of ductile material. 12.The method of claim 9 wherein the deformable member is formed of aninflatable chamber and the modifying step includes modifying the volumeof inflation fluid within the inflatable chamber.
 13. The method ofclaim 9 wherein the modifying step includes the step of extending adilator through the central passage and expanding the dilator to expandthe deformable member.
 14. The method of claim 9 wherein the modifyingstep includes applying compressive forces against the exterior of theprosthetic device to compact the deformable member.
 15. The method ofclaim 1 wherein the prosthetic device includes a longitudinal slitextending from the distal opening along a wall of the prosthetic device,and a zipper carriage engaged with wall sections adjacent thelongitudinal slit and moveable in a proximal direction to increase theeffective length of the slit and in a distal direction to decrease theeffective length of the slit, the modifying step including the step ofmoving the zipper carriage.
 16. The method of claim 1 wherein theprosthetic device includes a diaphragm extending at least partiallyacross the central passage, the diaphragm including a shutter definingthe distal opening and being rotatable between expanded and contractedpositions to increase and decrease the effective diameter of the distalopening, wherein the modifying step includes rotating the shutter. 17.The method of claim 1 wherein the providing step provides a cord forminga loop around at least a portion of the prosthetic device, and whereinthe modifying step includes adjusting the effective diameter of theloop.
 18. The method of claim 1 wherein the modifying step includesremoving a portion of the prosthetic device adjacent to the distalopening.
 19. The method of claim 18 wherein the removing step includescutting the prosthetic device using an energized electrode.
 20. Themethod of claim 18 wherein the removing step includes cutting theprosthetic device using a sharpened tool.
 21. The method of claim 18wherein the removing step includes cutting the prosthetic device using alaser.
 22. The method of claim 18 wherein the removing step includescutting the prosthetic device using a chemical stream.
 23. A medicaldevice positionable within a gastro-esophageal junction region of apatient having an esophagus and a stomach, the medical devicecomprising: a prosthetic device having a proximal opening, an exitorifice, and an central passage between the proximal opening and exitorifice, a proximal portion of the prosthetic device positionable withinthe gastro-esophageal junction region such that the proximal opening isin substantial alignment with the esophagus; and a flow restrictivecomponent on a distal portion of the prosthetic device, the flowrestrictive component moveable between a first position in which theexit orifice has a first size and a second position in which the exitorifice has a second size that is smaller than the first size.
 24. Themedical device of claim 23 wherein in the first position the flowrestrictive component is detached from to the prosthetic device andwherein in the second position the flow restrictive component isattached to the prosthetic device.
 25. The medical device of claim 24wherein the flow restrictive component is attachable to a distal portionof the prosthetic device.
 26. The medical device of claim 24 wherein theflow restrictive component is an insert positionable within the centralpassage.
 27. The medical device of claim 23 wherein the flow restrictivecomponent is a deformable member, wherein the first position is acompressed position and the second position is an expanded position. 28.The medical device of claim 27 wherein the deformable member is formedof malleable material.
 29. The medical device of claim 27 wherein thedeformable member is formed of ductile material.
 30. The medical deviceof claim 27 wherein the deformable member is formed of an inflatablechamber.
 31. The medical device of claim 23 wherein the flow restrictivecomponent includes a diaphragm extending at least partially across thecentral passage, the diaphragm including a shutter defining the distalopening and being rotatable between expanded and contracted positions toincrease and decrease the effective diameter of the distal opening. 32.The medical device of claim 23 wherein the flow restrictive componentincludes a cord forming a loop around at least a portion of theprosthetic device, the loop adjustable to a tightened position tocompress the prosthetic device.
 33. A method of treating obesity,comprising the steps of: providing a prosthetic device having a proximalopening and a central passage; securing the prosthetic device at thegastro-esophageal junction region of the patient, with the prostheticdevice oriented such that food ingested by the patient passes from theesophagus into the proximal opening; causing food ingested by thepatient to pass from the esophagus into the proximal opening and throughthe central passage, and to exit the prosthetic device through an exitorifice into the interior of the stomach; and modifying the size of theexit orifice.
 34. The method of claim 33 wherein the modifying step isperformed after the securing step.
 35. The method of claim 34 wherein:prior to the modifying step food ingested by the patient flows throughthe exit orifice at a first rate; and following the modifying step foodingested by the patient flows through the exit orifice at a second ratedifferent than the first rate.
 36. The method of claim 35 wherein thefirst rate is faster than the second rate.
 37. The method of claim 35wherein the first rate is slower than the second rate.
 38. The method ofclaim 33 wherein the modifying step is performed prior to the securingstep.
 39. The method of claim 33 wherein: the prosthetic device includesa pouch having a distal opening, and the method further provides a firstcomponent attachable to the pouch, the first component including adistal orifice having a size different than a size of the distalopening; the modifying step includes attaching the component to thepouch such that ingested food exiting the central passage flows throughthe distal orifice and into the stomach.
 40. The method of claim 39,further including the step of replacing the first component with asecond component, the second component having an second distal orificehaving a size different from the size of the first distal orifice. 41.The method of claim 39, further including the step of removing thecomponent from the pouch to further modify the size of the exit orifice.42. The method of claim 39 wherein the first component includes a flowrestrictive insert positionable within the central passage of the pouch.43. The method of claim 39 wherein the first component includes a flowrestrictive device attachable to an exterior portion of the pouch. 44.The method of claim 33, wherein the prosthetic device includes adeformable member coupled to the prosthetic device, and whereinmodifying step includes deforming the deformable member to modify thesize of the exit orifice.
 45. The method of claim 44 wherein thedeformable member is formed of malleable material.
 46. The method ofclaim 44 wherein the deformable member is formed of ductile material.47. The method of claim 44 wherein the deformable member is formed of aninflatable chamber and the modifying step includes modifying the volumeof inflation fluid within the inflatable chamber.
 48. The method ofclaim 44 wherein the modifying step includes the step of extending adilator through the central passage and expanding the dilator to expandthe deformable member.
 49. The method of claim 44 wherein the modifyingstep includes applying compressive forces against the exterior of theprosthetic device to compact the deformable member.
 50. The method ofclaim 33 wherein the prosthetic device includes a longitudinal slitextending from the distal opening along a wall of the prosthetic device,and a zipper carriage engaged with wall sections adjacent thelongitudinal slit and moveable in a proximal direction to increase theeffective length of the slit and in a distal direction to decrease theeffective length of the slit, the modifying step including the step ofmoving the zipper carriage.
 51. The method of claim 33 wherein theprosthetic device includes a diaphragm extending at least partiallyacross the central passage, the diaphragm including a shutter definingthe distal opening and being rotatable between expanded and contractedpositions to increase and decrease the effective diameter of the distalopening, wherein the modifying step includes rotating the shutter. 52.The method of claim 33 wherein the providing step provides a cordforming a loop around at least a portion of the prosthetic device, andwherein the modifying step includes adjusting the effective diameter ofthe loop.
 53. The method of claim 33 wherein the modifying step includesremoving a portion of the prosthetic device adjacent to the distalopening.
 54. The method of claim 53 wherein the removing step includescutting the prosthetic device using an energized electrode.
 55. Themethod of claim 53 wherein the removing step includes cutting theprosthetic device using a sharpened tool.
 56. The method of claim 53wherein the removing step includes cutting the prosthetic device using alaser.
 57. The method of claim 53 wherein the removing step includescutting the prosthetic device using a chemical stream.
 58. A method oftreating obesity, comprising the steps of: providing a base device and aprosthetic device having a proximal opening and a central passage;securing the base device at the gastro-esophageal junction region of thepatient; allowing tissue of the gastro-esophageal junction region to atleast partially heal for a period of time following the securing step;after the allowing step, attaching the prosthetic device to the basedevice, with the prosthetic device oriented such that food ingested bythe patient passes into the proximal opening; causing food ingested bythe patient to pass into the proximal opening and through the centralpassage, and to exit the prosthetic device through an exit orifice intothe interior of the stomach.
 59. The method of claim 58 wherein theperiod of time is at least one day.
 60. The method of claim 58 whereinthe period of time is more than one week.
 61. The method of claim 58,wherein the proximal opening is larger than the exit orifice.
 62. Themethod of claim 58 further including the step of modifying the size ofthe exit orifice.
 63. The method of claim 62 wherein the modifying stepis performed after the step of attaching the prosthetic device to thebase device.
 64. The method of claim 62 wherein: prior to the modifyingstep food ingested by the patient flows through the exit orifice at afirst rate; and following the modifying step food ingested by thepatient flows through the exit orifice at a second rate different thanthe first rate.
 65. The method of claim 64 wherein the first rate isfaster than the second rate.
 66. The method of claim 64 wherein thefirst rate is slower than the second rate.